U.S. patent application number 12/402809 was filed with the patent office on 2009-09-17 for seal for trocar.
This patent application is currently assigned to OERTLI-INSTRUMENTE AG. Invention is credited to Silvio Di Nardo, Bruno Nyffenegger.
Application Number | 20090234292 12/402809 |
Document ID | / |
Family ID | 39645071 |
Filed Date | 2009-09-17 |
United States Patent
Application |
20090234292 |
Kind Code |
A1 |
Di Nardo; Silvio ; et
al. |
September 17, 2009 |
Seal for Trocar
Abstract
A seal for use in a trocar, particularly for a trocar for eye
surgery, having a seal element, with a seal opening, and an
instrument opening. The instrument opening extends along a centre
axis on both sides of the seal element all the way through the
seal. The seal also has a clamp element for establishing a form-fit
connection to an instrument that is inserted at least partially
into the instrument opening and through the seal opening.
Inventors: |
Di Nardo; Silvio; (St.
Gallen, CH) ; Nyffenegger; Bruno; (Balgach,
CH) |
Correspondence
Address: |
THE WEBB LAW FIRM, P.C.
700 KOPPERS BUILDING, 436 SEVENTH AVENUE
PITTSBURGH
PA
15219
US
|
Assignee: |
OERTLI-INSTRUMENTE AG
Berneck
CH
|
Family ID: |
39645071 |
Appl. No.: |
12/402809 |
Filed: |
March 12, 2009 |
Current U.S.
Class: |
604/167.01 |
Current CPC
Class: |
A61F 9/007 20130101;
A61B 17/3462 20130101; A61B 2017/00477 20130101; A61B 2017/347
20130101 |
Class at
Publication: |
604/167.01 |
International
Class: |
A61B 17/34 20060101
A61B017/34 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 17, 2008 |
CH |
00394/08 |
Claims
1-15. (canceled)
16. A trocar, said trocar comprising a cannula with a centre axis,
a flange formed integrally on this cannula, an opening extending
along the centre axis through the cannula, and a receiving opening
that extends along the centre axis through the flange, said opening
and said receiving opening forming an opening that runs all the way
through the trocar, wherein a seal is arranged in the receiving
opening of the trocar, wherein said seal comprises: a seal element,
having a seal opening; an instrument opening, which instrument
opening extends along a centre axis on both sides of the seal
element all the way through the seal; and a clamp element for
establishing a form-fit connection to an instrument that is
inserted at least partially into the instrument opening and through
the seal opening.
17. The trocar according to claim 16, wherein the receiving opening
comprises a circumferential groove in which a circumferential
flange of the seal engages in order to establish a form-fit
connection between the trocar and seal.
18. The trocar according to claim 16, wherein the seal is injected
directly into the receiving opening of the trocar by a plastics
injection-moulding technique.
19. The trocar according to claim 16, wherein the outer
circumferential surface of the seal faces and is in contact with
the circumferential surface of the opening in the trocar.
20. The trocar according to claim 16, wherein the trocar and the
seal are produced in one piece from a plastic.
21. A seal for use in a trocar, said seal comprising: a seal
element, having a seal opening; an instrument opening, which
instrument opening extends along a centre axis on both sides of the
seal element all the way through the seal; and a clamp element for
establishing a form-fit connection to an instrument that is
inserted at least partially into the instrument opening and through
the seal opening.
22. The seal according to claim 21, wherein the clamp element is
designed in one piece with the seal.
23. The seat according to claim 21, wherein the seal element is a
membrane which extends substantially perpendicular to the centre
axis of the seal, and the seal opening comprises at least one
slit.
24. The seal according to claim 21, wherein the clamp element is
arranged before the seal element, seen in the direction of
insertion of an instrument.
25. The seal according to claim 21, wherein the clamp element is
designed as a circumferential clamping bead, which reduces the
diameter of the instrument opening.
26. The seal according to claim 21, wherein the clamp element is
designed as a clamping bead divided into sections, at least three
clamping bead sections being formed which reduce the diameter of
the instrument opening.
27. The seal according to claim 21, wherein the clamp element is
designed as a groove extending about a complete circumference or as
a groove divided into sections.
28. The seal according to claim 21, wherein the seal comprises a
circumferential flange on its outer face.
29. A kit, said kit comprising a trocar and an instrument which is
designed for ophthalmology and can be guided through the trocar,
wherein said trocar comprises a cannula with a centre axis, a
flange formed integrally on this cannula, an opening extending
along the centre axis through the cannula, and a receiving opening
that extends along the centre axis through the flange, said opening
and said receiving opening forming an opening that runs all the way
through the trocar, wherein a seal is arranged in the receiving
opening of the trocar, wherein said seal comprises: a seal element,
having a seal opening; an instrument opening, which instrument
opening extends along a centre axis on both sides of the seal
element all the way through the seal; and a clamp element for
establishing a form-fit connection to an instrument that is
inserted at least partially into the instrument opening and through
the seal opening; wherein the instrument comprises a section that
is complementary to the clamp element, the clamp element or the
instrument or both being designed in such a way that they can be
compressed during insertion of the instrument into the seal and
such that the original shape of these parts can be recovered when
the predefined depth of insertion is reached, such that the surface
of the clamp element is in contact with the surface of the
complementary section of the instrument, such that a form-fit
connection is established between seal and instrument.
30. The kit according to claim 29, wherein the complementary
section has the shape of a groove which extends about a complete or
partial circumference and into which the bead of the clamp element
engages.
31. The kit according to claim 29, wherein the complementary
section has the shape of a bead which extends about a complete or
partial circumference and which can be received by a groove
arranged on the clamp element.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a seal for a trocar
according to the features of the preamble of Claim 1 and to a
trocar with a seal according to the features of Claim 9.
PRIOR ART
[0002] Trocars with seals, or seals for trocars, are known from the
prior art and are used by specialists in a large number of
operations on the eye.
[0003] In most cases, three trocars are normally used in an
operation on the eye. Each trocar, also referred to as a guide
tube, is introduced into the eye in such a way that the tip of the
trocar extends into the vitreous body (corpus vitreum) of the eye,
while the opposite end is available as an attachment. The eye in
most cases has to be supplied with an infusion, which is done by
way of what is called the infusion trocar. Two further trocars are
also used in most cases. Suitable instruments or lighting devices
can then be advanced to the eye through these further trocars.
These further trocars are also referred to as instrument trocars or
illuminating trocars.
[0004] A seal has to be provided between the trocars and the
inserted instrument in order to avoid escape of a fluid when the
trocar is in place. For example, the company DORC has started
fitting a kind of cap on the flange of the trocar, which cap
provides the seal between trocar and instrument. However, such a
cap has the disadvantage of increasing the external diameter of the
trocar.
[0005] U.S. Pat. No. 5,865,807 discloses a further seal that can be
arranged in the inside of a trocar. This seal has two sealing
locations. This is advantageous as regards the quality of the seal
but has the disadvantage that the instruments have to be pushed in
the longitudinal direction through two seals, causing greater
forces to act on the eye.
DISCLOSURE OF THE INVENTION
[0006] Starting out from this prior art, it is an object of the
invention to make available a trocar seal that overcomes the
disadvantages of the prior art. Moreover, a trocar is to be made
available which permits easy connection of an instrument or
infusion attachment to the trocar.
[0007] This object is achieved by a trocar seal having the features
of Patent Claim 1. Advantageous embodiments of the invention are
set forth in the dependent claims.
[0008] Accordingly, such a seal comprises a seal element, with a
seal opening, and an instrument opening, which instrument opening
extends along a centre axis on both sides of the seal element all
the way through the seal, and the seal also comprises a clamp
element for establishing a form-fit connection to an instrument
that is inserted at least partially into the instrument opening and
through the seal opening.
[0009] An advantageous trocar according to the invention has a seal
of this kind fitted in it. By means of an outer circumferential
bead on the seal, a form-fit connection can advantageously be
achieved with a complementary recess in the inside wall of the
trocar, such that insertion and extraction forces applied to this
system by an instrument do not lead to a displacement of the seal
in the trocar, although a reliable connection of the instrument or
infusion attachment to the trocar is permitted.
[0010] Further advantageous embodiments are characterized in the
dependent claims.
BRIEF DESCRIPTION OF THE DRAWING
[0011] Examples of preferred embodiments are described in more
detail below with reference to the drawing, in which:
[0012] FIG. 1 shows a cross-sectional view of a trocar with a seal
according to the invention;
[0013] FIG. 2 shows a cross-sectional view of the trocar with the
seal according to FIG. 1, and with an infusion attachment;
[0014] FIG. 3 shows a cross-sectional view of the trocar with the
seal according to FIG. 1, and with an instrument;
[0015] FIGS. 4a and 4b show a schematic plan view of the seal
membrane of the seal; and
[0016] FIGS. 5a and 5b show a schematic cross-sectional view of the
seal membrane, the cross-section being taken along the centre
axis.
DESCRIPTION OF PREFERRED ILLUSTRATIVE EMBODIMENTS
[0017] Possible illustrative embodiments are described with
reference to the drawings. The drawings and the description show
preferred illustrative embodiments and should not be interpreted in
such a way as to limit the invention, which is defined by the
claims.
[0018] FIG. 1 shows the cross-sectional view of a trocar 1 with a
seal 2. Such a trocar is used in eye surgery.
[0019] The trocar 1 principally comprises a cannula 10, and a
flange 11 formed integrally on this cannula 10. The cannula 10 has
a smaller diameter than the flange 11. The cannula 10 is inserted
into the eye via an incision in the eye. The flange 11 comes to lie
in such a way that its surface 11a extending perpendicular to the
cannula comes to lie on the surface of the eye. The transition
between cannula 10 and flange 11 is preferably rounded.
[0020] Both the cannula 10 and the flange 11 are preferably
substantially cylindrical and extend along a centre axis 19. The
outer contour of the cannula 10 is conical in the lower area 10a,
which is introduced first into the eye, thus ensuring that the
trocar 1 is inserted as easily and smoothly as possible.
[0021] A cylindrical opening 12 extends through the cannula 10
along the centre axis 19 thereof. In the area of the flange 11, the
cylindrical opening 12 merges into a receiving opening 15, which is
of greater diameter and extends all the way through the flange 11.
An opening 12, 15 is thus created that extends through the entire
trocar 1.
[0022] The receiving opening 15 serves to receive the seal 2
described below. For this purpose, the receiving opening 15 has, in
its distal area, a circumferential recess 16 which extends into the
flange 11 near the top face 14 of the receiving opening 15. In the
upper area 15a before the recess 16, the receiving opening has a
greater diameter than in the proximal, lower area 15b directed
towards the cannula 10. The receiving opening 15 also has a greater
diameter than the opening 12 extending through the cannula 10. The
transition between the receiving opening 15 and the opening 12 is
designed with a bevel 17. A further bevel 18 is also provided at
the transition from the recess 16 to the lower area 15b. The recess
16 can also be configured differently, provided that it establishes
a connection, preferably a form-fit connection or, if appropriate,
a force-fit connection to the seal 2. The function of the recess 16
is therefore to hold the seal 2 in the trocar 1.
[0023] The trocar 1 further comprises an outer circumferential
groove 13, which is here arranged in the area of the flange 11. The
groove 13 is formed into the circumferential surface 11b of the
flange 11. The circumferential groove 13 can be easily gripped by
forceps, such that the trocar 1 can be suitably placed in the eye
or removed again.
[0024] The seal 2 is likewise shown in a cross-sectional view in
FIG. 1. The seal 2 comprises an instrument opening 20 that extends
along a centre axis 29 of the seal 2 and essentially through the
entire seal 2. The centre axis 29 of the instrument opening 20 is
flush with the centre axis of the trocar 1 here. The instrument
opening 20 serves basically for guiding the instruments that are to
be guided through the trocar 1. The seal 2 further comprises a seal
membrane 21 with a seal opening 22. The seal membrane 21 extends
perpendicular to the centre axis 29 and divides the instrument
opening 20 into an upper section 20a and a lower section 20b.
[0025] The seal opening 22 is designed as a slit 22a, formed
radially with respect to the centre axis 29, in the seal membrane
21. The radially formed slit 22a is shown in FIG. 4a, which shows a
schematic detail of the seal membrane 21 in plan view. The slit 22a
runs in two radial lengths from the centre axis 29 to cover, for
example, 2/3 of the diameter of the instrument opening 20. The slit
and the seal membrane 21 are dimensioned in such a way that they
can withstand a pressure of up to 0.1 bar or, in another
illustrative embodiment, of 0.2 bar, which acts on the seal
membrane 21 from the lower section 20b, and can thus maintain a
sealing action. In the case of use of the trocar 1, said pressure
is an intraocular pressure. In other words, this means that the
seal membrane 21 and the seal opening 22 can also seal off the
opening through the entire trocar 1 even when there is no
instrument guided through the trocar 1 and through the seal 2.
[0026] In other embodiments, for example as shown in FIG. 4b, three
slits 22b run in the radial direction from the centre axis 29. The
slits are arranged at an angle of 120.degree., for example. Other
arrangements of the slits are also conceivable.
[0027] The upper section 20a of the instrument opening 20 also
comprises a clamp element 23. The clamp element 23 is designed in
such a way that it can establish a releasable form-fit connection
to an instrument that is to be inserted, such that an axial
displacement of the instrument relative to the trocar 1 can be
avoided. For this purpose, the clamp element 23 extends from the
top surface of the instrument opening 20 into the instrument
opening 20, such that the diameter thereof is reduced in the area
of the clamp element 23. It can generally be said, accordingly,
that the seal 2 serves not only as a seal element but also as a
securing element or clamp element.
[0028] In the present illustrative embodiment, the clamp element 23
is designed as a convex circumferential clamping bead. The clamping
bead forms the first part of the upper section 20a of the
instrument opening 20. After the clamping bead, the surface of the
instrument opening 20 merges into a concave rounding 24. The
concave rounding 24 is adjoined by a bevel 25, which merges into
the seal membrane 21. The bevel 25 reduces the diameter of the
instrument opening 20 towards the seal membrane 21.
[0029] It is advantageous that the clamp element 23 is arranged
opposite the upper area 15a and the recess 16 is such a way that
radially acting forces, during insertion or withdrawal of an
instrument, ensure that there is no longitudinal displacement of
the seal 2 in the trocar 1.
[0030] In other illustrative embodiments, it is conceivable, for
example, for the clamping bead 23 to be divided into sections. The
upper section 20a can also be designated as coupling section or
snap-in section. Moreover, it is also conceivable to designate the
clamping bead as snap-in fastener.
[0031] During insertion of an instrument 3, the clamp element 23 is
slightly deformed by parts of the instrument 3. That is to say, in
the case of a fixed recess 16, the clamping bead 23 can be slightly
compressed upon insertion of the instrument, so as to allow the
instrument to be inserted. The instrument 3 has a section designed
complementary to the clamp element 23. That is to say, the
complementary section of the instrument 3 has, when seen in a
cross-sectional view, the shape that is the diametrical opposite of
the corresponding section of the clamp element 23. As soon as the
instrument 3 has been advanced such that it has reached the desired
depth of insertion, the clamp element 23 recovers its original
shape. The clamping bead 23 then engages in the complementary
section, which in this case has a corresponding depression or
groove. This engagement or latching has the effect that a form-fit
connection can be established between the instrument 3 and the seal
2. The complementary section can also be designated as coupling
section 34. Generally, a form-fit connection is understood as a
connection of two elements in which parts of one element engage in
sections of complementary shape of the other element, such that a
relative movement of the two elements can be prevented up to a
point where a certain force is applied.
[0032] In an alternative embodiment, the clamp element 23 could
also be designed as a groove, in which case the instrument then
comprises the complementary bead.
[0033] The lower section 20b of the instrument opening 20 extends
slightly conically from the seal membrane 21, such that the
internal diameter of the instrument opening 20 becomes greater away
from the seal membrane 21, seen in the direction of the centre axis
29. The instrument opening 20 in this lower section 20b can also be
designated as membrane receiver, since the seal membrane 21 comes
to lie in this area when an instrument is guided through. The outer
wall in this section also extends slightly conically in the
direction from the seal membrane, as a result of which a small gap
5 forms between the wall of the receiving opening 15 and the outer
wall of the seal 2. The gap 5 has basically two functions. When
fitting the seal 2 in the trocar 1, the insertion of the seal 2 is
made easier since in this area there is no contact between seal 2
and trocar 1, which means that no frictional forces arise. Upon
insertion of an instrument through the seal 2, the seal is able to
deform outwards, that is to say towards the trocar 1. In this way,
the surgeon is able to insert the instrument with less axial force
being applied.
[0034] On the outside, the seal 2 has a circumferential flange 26
in the upper area. The circumferential flange 26 is designed in
such a way that it is complementary to the recess 16 and is in
engagement with the latter. The seal also has an outer bevel 27,
which is in engagement with a bevel 18 of the opening 15. The
connection between flange 26 and recess 16 permits a good
connection between seal 2 and trocar 1. By virtue of the design,
axial forces and also radial forces can be compensated. To put it
another way, the shape of the outside of the seal 2 in the upper
area 20a is substantially congruent to the shape of the inside wall
of the receiving opening 15.
[0035] The seal 2 is preferably made from a silicone polymer. The
silicone polymer preferably has a Shore hardness in the range of
Shore 70 to Shore 80. Other Shore hardness values are also
conceivable, however. It is also possible to use other plastics, in
particular thermoplastic elastomers (TPE), for the seal. The trocar
1 is made of metal, for example instrument-grade steel, titanium or
a titanium alloy, or of a plastic with a sufficient stiffness. The
materials used must be biocompatible.
[0036] The seal 2 is preferably inserted into the receiving opening
15 along the centre axis 19. By virtue of the above-described shape
of the seal, a form-fit connection is established between the seal
2 and the trocar 1. In alternative illustrative embodiments, it is
also conceivable for the seal 2 to be adhesively bonded or to be
injected directly into the receiving opening 15 by a plastics
injection-moulding technique. For example, a two-component
injection-moulding technique can be used here. Alternatively, the
trocar 1 and the seal 2 can also be designed in one piece.
[0037] As is shown, the seal 2 is arranged fully within the trocar
1. This is advantageous since, in contrast to other sealing
arrangements, the diameter of the trocar 1 is not increased. The
ophthalmic surgeon therefore has a better view of the eye that is
to be operated on, and he is better able to handle the trocars.
[0038] FIG. 2 shows the trocar 1 and the seal 2, with an infusion
attachment 3 connected to the trocar 1 and to the seal 2. The
infusion attachment 3 in this case comprises a coupling piece 30
and an attachment tube 31.
[0039] The coupling piece 30 comprises a through-opening 32, a hose
attachment section 33 and a coupling section 34. The
through-opening 32 serves to receive the attachment tube 31 and
extends along a centre axis 39 all the way through the coupling
piece 30. The attachment tube 31 protrudes beyond the coupling
piece 30 in the axial direction.
[0040] The hose attachment section 33 serves to connect the
coupling piece 30 to an infusion line and is designed
accordingly.
[0041] The coupling section 34 has a design substantially
complementary to the upper section 20a of the instrument opening
20. In the front area, the coupling section 34 has the shape of a
cone 35. The cone 35 is adjoined by a convex rounding 36, which
merges into a concave rounding 37. The concave rounding 37 adjoins
the coupling section 34. As has been mentioned above, the coupling
section 34 is adjoined by the hose attachment section 33. In the
area directly adjoining the coupling section 34, the hose
attachment section 33 has an abutment surface 38 extending
perpendicular to the centre axis.
[0042] When the infusion attachment 3 is inserted into the trocar 1
and into the seal 2, the attachment tube 31 passes, in a first
step, through the seal opening 22 in the seal membrane 21. A
leaktight contact arises between seal opening 22 and attachment
tube 31. The sealing location is designated by reference sign D.
The seal membrane 21 is thus displaced into the membrane receiver
or lower section 20b of the instrument opening 20.
[0043] In a second step, the cone 35 impacts the clamp element 23.
The clamp element 23 is thus compressed in the radial direction,
such that the infusion attachment 3 can be moved farther in the
axial direction. The infusion attachment 3 is moved in the axial
direction until the concave rounding 37 comes to lie at the level
of the clamp element 23. In other words, this means that the clamp
element 23 fills the concave rounding 37. A form-fit connection is
thus established between the seal 2 and the infusion attachment 3.
This form-fit connection can also be designated as snap-fit
connection, since the coupling section 34 snaps into or latches in
the upper section 20a or the coupling section. The form-fit,
latched-in connection is particularly advantageous since in this
way the infusion attachment is held firmly and stabilized in the
trocar 1. By virtue of the congruent form of the two coupling
sections 20a and 34, the connection is additionally stabilized with
respect to transverse forces, which occur transverse to the centre
axes.
[0044] When removing the infusion attachment 3, the tensile force
has to be slightly increased, such that the clamp element 23 is
again suitably compressed. It is important that the holding forces
upon release of the coupling section 34 from the concave rounding
or circumferential groove 24 are smaller than the forces that act
between the recess 16 and the upper section 20a of the seal 2.
[0045] FIG. 3 shows an instrument 4 which is connected to the
trocar 1 and to the seal 2. The instrument 4, for example a light
source or a cutting instrument, is shown here with a cylindrical
rod or mandrel 40. In analogy with the connection described above,
the instrument 4 with the mandrel 40 is pushed along its centre
axis into the trocar 1 and seal 2. In so doing, the mandrel 40,
like the attachment tube 31, penetrates the seal membrane 21 or
seal opening 22. A leaktight contact is again achieved between the
seal opening 22 and the surface of the mandrel 40. Moreover, the
instrument 4 can be moved with a slight force along the centre
axis, without negatively affecting the sealing action between the
mandrel 40. The mandrel 40 can, for example, be a 23-gauge mandrel.
Alternatively, the mandrel 40 can also be a 25-gauge mandrel or a
20-gauge mandrel. That is to say, the trocar 1 and the seal 2 can
receive 20-gauge, 23-gauge and 25-gauge instruments. Other
diameters are likewise conceivable.
[0046] As soon as the infusion attachment 3 or the instrument 4 is
removed from the trocar 1 and from the seal 2, the seal membrane 21
or seal opening closes on account of the elastic properties of the
seal membrane 21. This is particularly advantageous, since no
fluids can escape from the eye after removal of the instruments 3,
4.
[0047] It is clear from FIGS. 3 and 5a that the underside of the
curved seal membrane 21 is flat and extends perpendicular to the
boundary surfaces of the seal membrane 21 itself. In other words,
this means that the slit or the slits of the seal opening 22 extend
substantially perpendicular to the surface of the seal membrane 21,
that is to say parallel to the centre axis 19, 29. The two side
walls 22c and 22d of the slits are accordingly perpendicular to the
surface of the seal membrane 21.
[0048] In other illustrative embodiments, as shown in FIG. 5b, it
would also be possible for the slit or slits of the seal opening 22
to be at an angle to the axis 19, 29. The side walls 22c and 22d
are accordingly at an angle to the centre axis 19, 29 and at an
angle to the surface of the seal membrane 21.
LIST OF REFERENCE SIGNS
[0049] 1 trocar
[0050] 2 seal
[0051] 3 infusion attachment
[0052] 4 instrument
[0053] 5 gap
[0054] 10 cannula
[0055] 10a conical part
[0056] 11 flange
[0057] 11a surface
[0058] 11b circumferential surface
[0059] 12 opening
[0060] 13 circumferential groove
[0061] 14 top face of flange
[0062] 15a upper area of receiving opening
[0063] 15b lower area of receiving opening
[0064] 16 recess
[0065] 17 bevel
[0066] 18 bevel
[0067] 19 centre axis
[0068] 20 instrument opening
[0069] 20a upper section
[0070] 20b lower section
[0071] 21 seal membrane
[0072] 22 seal opening
[0073] 22a,b slits
[0074] 22c,d side walls of the slits
[0075] 23 clamp element
[0076] 24 concave rounding
[0077] 25 bevel
[0078] 26 circumferential flange
[0079] 27 bevel
[0080] 29 centre axis
[0081] 30 coupling piece
[0082] 31 attachment tube
[0083] 32 through-opening
[0084] 33 hose attachment section
[0085] 34 coupling section
[0086] 35 cone
[0087] 36 concave rounding
[0088] 37 concave rounding
[0089] 38 abutment surface
[0090] 39 centre axis
[0091] 40 mandrel
* * * * *